This invention relates to the testing of the degree of vacuum in an evacuated vial, and in particular to an apparatus for testing the degree of vacuum by ionizing the gas within the vial and measuring the ionization current, which is directly representative of the value of the vacuum within the vial.
Evacuated vials can be tested without opening the vial or inserting any test probe or other device into the vial, which may compromise the integrity of the contents within the vial, or destroy the vacuum. U.S. Pat. No. 4,546,319 discloses an automated method and apparatus for testing the vacuum of a series of vials which may be proceeding down a conveyer system. While the apparatus of this patent successfully test vials, because of its size and complexity, the apparatus of the invention proves to be relatively expensive. For small operations not requiring an assembly line-type vacuum investigation, the apparatus of this invention is prohibitively expensive.